Rotative dry vacuum-pump



W. LONSDALE.

ROTATIVE DRY VACUUM PUMP.

APPLICATION FILED MAY 6, I920.

Patented M31- 8, 1921.

2 SHEETS-SHEET 1.

/NI/ENTOR w. LONSDALE.

ROTATIVE DRY VACUUM PUMP.

APPLICATION FILED MAY 0, 1920.

Patented Mar. 8, 1921.

2 SHEETSSHEET 2.

IN l/EIVTOR UNITED STA'ILELS PATENT OFFICE.

WILLIAM LONSDALE, F ELIZABETH, NEW JERSEY, ASSIGNOR TO WHEELER CONDENSER AND ENGINEERING COMPANY, OF CARTERET, NEW JERSEY.

BOTA'IIVE DRY VAGUUIVLPUMP.

. Specification of Letters Patent.

Patented Mar. 8, 1921.

Application filed May 6, 1920. Serial No. 379.212.

all whom it may can 009%.

Be it known that I, VILLIAM LoNsDALn, a citizen of the United States, residing at Elizabeth. in the county of Union, State of New Jersey, have invented an Improvement in Rotative Dry Vacuum-Pumps, which the following is a specification.

This invention relates to a rotative vacuum pump and more particularly to the pump ves and the manner of cooling the same or maintaining the valves and valve ports a predetermined temperature. Heretolore. much di'fiiculty has been experienced in providing a water or other cooling jacketl'or the outside of the valve ports of rotai'ive dry vacuum pumps and similar structures, and in fact, so far as I am aware,such cooling jackets are impractical. In the use of; the pumps to which this invention relates, diificulty has also been experienced due to the heating of the valves and valve ports and the resultant carbon deposits from the cylinder oils employed to lubricate the pistons of the engines with which the pumps are employed. In the higher grade cylinder oils there is comparatively little carbon deposit, but in the lower grade oils commonly employed the carbon deposit often becomes so excessive as to impair the efficiency of the pump, and the object of my present invention is to overcome this difliculty by employing a structure in which the valves of the pump are cooled by circulating water or other equivalent medium so as to maintain the same at a predetermined and sufliciently low temperature to prevent the volatilization of the cylinder oils in passing through the pump and the consequent carbon de-,

posits which accumulate in the valve ports, whereby it has been found quite possible to use relatively low grade cylinder oils without the accumulation of these deposits. It will be understood that while I have herein shown and described the invention as applicable to rotative dry vacuum pumps the same may be used in compressors and other apparatus where and when occasion may require. 1

In the drawing:

Figure l is a sectional view taken through the valve chest of a rotative dry vacuum pump.

Fig. 2 is a transverse section of the valve.

Fig. 3 is a longitudinal section of the cooling medium head showing the same in position at in Fig. 1.

Fig. 4 is a view similar to Fig. 1 showing another form of the invention, and

Fig. 5 is a section of the cooling medium head employed in the structure shown in 4 but taken at right angles to the posltion in which this part is illustrated in Fig. 4.

Referring to the drawing and particularly to Figs. 1, 2 and 3, the pump body or a portion thereof is indicated at and the cylinder of the pump at 11. As is'oustomary the pump body is provided with valve chests 12 and 13, the former of which is fitted with a chest head .14 and the latter with a chest head 15.

Centrally the chest head i l is provided with a bore adapted to receive a tube 1.6 which, at its inner end, is flanged as indicated at 17 so as to be set into one head of the valvelS and is secured in position therein by means of screws 18' or otherwise. The tube 16 extends appreciably beyond the face of the chest head 14, and associated with the extension and the chest head I employ a water head and gland 19. This water head and gland 19 may be secured in position in the chest head by means of bolts 20 or otherwise. I also employ a supply pipe 21 for the. admission of the cooling water or other cooling medium, and at one end this supply pipe 21 is secured in the water head and gland 19 with the orifice at the end of the supply pipe preferably coincident with the face or end of the water head and gland 19 so that the cooling medium whether water or its equivalent may be supplied from any suitable source to this orifice 22 at this end of the supply pipe. This water head and gland is also provided in the side thereof with an opening 23 which serves as a discharge outlet as will be hereinafter more particularly described. The supply pipe 21 extends entirely through the space in the valve 18 longitudinally thereof and at its opposite end is supported or secured in a lug 24 which is adjustably mounted in the opposite head 25 of the valve. At this end of the supply pipe the same is provided with series of openings or holes 26 for the escape of the cooling medium from the supply pipe to the chamber or space within the valve. The valve 18 as is customary in pumps of this type is cylindrical and provided with trans right angles to that illustrated versely curved walls 27 and 28 with a passage 29 between the same for making commun1cat1on between the ends of the cylinder for equalizing the pressure at the ends of the piston strokes, and a space 30 providing communication, when the valve is in the correct position, between the inlet to the pump and the cylinder ends, and a space 31 providing communication, when the valve is in proper positions, between the ends of the cylinder and the discharge ports.

In the use of this apparatus, the water or other cooling medium employed is supplied to the pipe 21 through the orifice 22 and passes through the supply pipe to the opposite end of the valve, then flows throughthe holes 26 in the supply pipe into the chamber in the valve,'returning in the op-' posite direction through this chamber to the space between the supply pipe and the tube 16 so as to be withdrawn from the valve at the outlet or discharge orifice 23.

By reference to Figs. d and 5, it will be seen that I may dispensewith the supply pipe 21 and provide the gland 1.9 with a head 32 which has an inlet opening in the side thereof for the cooling medium so that the cooling medium may pass directly through the tube 16 into the chamber in the valve and flow but one waytherethreugh, being discharged through the opening in the opposite head otthe valve and passing through the bore 35 to the discharge outlet 36 in 'the valve stem 37. Obviously, the same results are obtained in this structure as those described in connection with the preferred'form of the invention. It will be equally obivious that the invention is not restricted to "the specific ructures herein shown and described, as the chamber in the valve may be, for example, partitioned and the water caused to flow through the same in various courses either lon 'itudinally, thereof or transversely thereof, or, for a further example, the chamber in the valve might be fitted with banks of tubes in the same manner that certain types of surface condensers a e made and the same results obtained without departing from the nature "withdrawing the cooling medium therefrom.

2. In a rotative dry vacuum pump, a valve chest, a rocker valve having a chamber therein, and means at the same end of the valve chest for admitting a cooling medium to the chamber in the valve and WltllClI'EtWlIlg the cooling medium therefrom. 3. In a rotatlve dry vacuum pump, a

body member, a valve chest, a valve adapted to oscillate in the valve chest, a her i member. connected to the valve chest and prov led with means for admitting a cooling medium to the same and through the valve chest into the chamber in the valve, and for withdrawing the cooling medium from the chamber in the valve in order to mainmedium from the chamber in the valve in order to maintain the valve at a predetermined temperature.

5. In a rotative dry vacuum pump, a body member, a valvechest, a rocker valve in the valve chest and having a chamber therein, a head and gland member secured to the valve chest, tubular member mountedsin the valve chest, a supply pipe secured in the head and gland member and ing through the said into the cha her in the valve for atlllllttlll a cooling medium to the cluimber in the valve, and means for withdrawing the cooling medium from the chamber in the valve in order to maintain the valve at a predetermined temperature.

'6. In a rotative dry vacuum pump, a body member, a valve chest-,a rocker valve in the valve chest and having a chamber.

therein, a head and land member secured to the valve chest, a tubular member mounted in the valve chest, a supply pipe connected at one end in the said head and gland memberentending through the said tube'in position space l therefrom and through the chamber in the said valve, and a support for the inner end of the said supply pipe in the opposite end or the said valve, the said supply pipe at its inner end heing provided with a series of holes whereby the cooling medium after passing through the supply pipe admitted to the chamber in the valve and is withdrawn therefrom through the space between the supply pipe and the saidtube and through an outlet orifice in the said land d,

Si ned by me this 20 day of April, 1920.

, wrLLIAMLoNsni-ms, 

